1. Field of the Invention
The present invention relates to elongate structural members for use in load bearing frames. More particularly the invention is concerned with structural members that are cold formed from sheet metal and utilized in triangulated frames wherein the rigidity of the frame as a whole results from the triangular arrangement of the members.
2. Description of the Prior Art
Elongate structural members that are cold formed from sheet metal are known in the art and are formed by example by rolling, folding or pressing a metal strip to achieve a cross section which is essentially either a channel, C-section, Z-section or I-section. These prior structural members are defined by a web having flanges projecting from the edges of the web and are formed from a steel strip of relatively thin dimension.
The structural members heretofore described have found wide spread usage as structural members in wall frames and roof trusses in dwellings such as sheds and small commercial buildings and the like. With the advent of increasing lumber costs, it has now become competitive that cold formed sheet metal structural members can be used in the construction of houses and other small buildings. This building industry is highly competitive and every effort is made to contain costs with respect to the structural members themselves and the manner in which they are formed into other structural members, such as roof truss. It is therefore desirable to have a cold form metal structural member that is easily fabricated and exhibits exceptional structural strength even when fabricated of relatively thin sheet metal so as to eliminate any catastrophic failures when the member is utilized to form other structural members.
An object of the present invention is to provide for a novel elongate, cold formed, metal structural member fabricated out of relatively thin sheet metal, yet exhibiting exceptional load bearing capacity.
A further object of the present invention is to provide for a novel elongate, cold formed, metal structural member which is easily manufactured and lends itself to efficient on cite assembly.
The invention comprises a cold formed, elongate, sheet metal structural member having a web portion having two longitudinally extending edges, there being a first tubular flange extending along one edge and projecting laterally to both sides of the web and a second tubular flange extending along the opposing edge and projecting laterally to one side only of the web, each of the tubular flange members having an elongate margin juxtaposed the web, one of the tubular flange members having its elongate margin secured to the web member.